We plan to develop novel site-based models of transport through ion channels in biological membranes, with an emphasis on development of skills required for a career in quantitative biology. A deeper understanding of transport and gating in ion channels is key to understanding the basic operation of ion channels and the effects of drug and illness on the nervous system. Recent discovery of the x-ray structure of the K+ ion channel from Streptomyces lividans makes this work especially timely. Using the x-ray structure, the energy profile of a test particle will be determined within the selectivity filter of the ion channel Ion fluxes determined by patch-clamp recording will be used to derive parameters used in the site model of transport through single-file channels at low ionic concentrations. The site model will need to account for an externally imposed electric field in a manner consistent with the Poisson equation,. Current voltage relationships predicted by this single ion site model will be compared with experiment and continuum theories, e.g. (PNP). The site model will be modified to allow for electrostatic interactions between multiple ions in the channel. The predictions of this model will then be compared with patch clamp experiments and PNP theory at higher ionic strengths.